Here is something that surprises a lot of people: a hair growth serum, a hair growth shampoo and a hair supplement can share ingredients and still do quite different jobs. In the CtoMi range, the serum and the shampoo both list Redensyl, Copexil and Copyrrol, and saw palmetto turns up in all three. So the useful question is not which one is best. It is what each one is built to do, and whether your routine needs one, two or all three of them.
This guide puts the three side by side: how each one is used, where it fits in your day, what it is good at and where it falls short. It sticks to what the labels say and leaves the big promises out, because everyone's hair is different and no product can promise the same outcome for every person.
Serum vs shampoo vs supplement at a glance
The quickest way to see the difference is to compare how each product is actually used. All three rows below follow the directions printed on the CtoMi product pages.
| Hair growth serum | Hair growth shampoo | Hair supplement | |
|---|---|---|---|
| Format | Leave-in liquid with a dropper | Rinse-off wash | Capsule taken by mouth |
| Where it goes | Directly onto the scalp | Through wet hair and onto the scalp | Swallowed with your daily routine |
| How often, per the label | 1ml nightly | Each time you wash | 1 capsule daily |
| Contact with the scalp | Left on overnight | Rinsed off after a short wait | None, it works from the inside |
| CtoMi example | PROSPER Follicle Booster Serum 30ml | THRIVE Hair Growth Shampoo 300ml | Hair & Follicle Nutrition |
| Main thing to get right | Getting it onto the scalp, not the lengths | Giving it time on the scalp before rinsing | Taking it every day as directed |
Read across any row and the pattern is clear. These are not three versions of the same thing. They reach your scalp in different ways and ask different things of you, which is why the choice is really about how they fit together.
Option 1: a hair growth serum
A serum is the only one of the three that stays where you put it. You apply it to the scalp, massage it in and leave it there, so it is the most targeted of the three formats. That is also why it asks the most of your routine: it only does its job if you actually apply it, night after night.
The PROSPER hair growth serum comes in a 30ml bottle, and each dropper delivers approximately 1ml. The label directions are simple: apply 1ml, one full dropper, directly to the scalp nightly, focus on thinning areas, massage gently for one to two minutes and leave it on overnight. Its key ingredients are Redensyl, BeriCos Copexil and Copyrrol, Superox-C AF from Kakadu plum (rich in vitamin C, for antioxidant support), saw palmetto extract and harakeke, the New Zealand flax, which is there to help keep the scalp hydrated. The full ingredient list also includes caffeine, jojoba seed oil and green tea leaf extract.
Where a serum shines:
- It stays in contact with the scalp overnight instead of being rinsed away.
- The measured dropper makes the amount easy to keep the same each night.
- You can place it exactly where you want it, such as along a part line or across the crown.
Where a serum falls short:
- It needs a nightly habit, and skipped nights are the most common way a serum routine fades out.
- It only covers the areas you apply it to.
- It is for external use only and does nothing for the nutrition side of hair care.
Option 2: a hair growth shampoo
A shampoo has the opposite strength. It slots into something you already do, so there is no new habit to build. The trade-off is contact: whatever is in the shampoo is on your scalp only while you wash, and then it goes down the drain.
THRIVE Hair Growth Shampoo comes in a 300ml bottle. The directions are to place a small amount in the palm of your hand, rub it slowly through wet hair, allow 30 seconds for the shampoo to work down towards the follicle, then rinse thoroughly. That short wait is the step most people skip. The formula lists Redensyl, Copexil and Copyrrol, saw palmetto, harakeke and mamaku black fern, which are included to hydrate and soothe the scalp, along with spirulina, ginger root and liquorice root.
Where a shampoo shines:
- It replaces a step you already take, so it is the easiest of the three to keep up.
- It leaves you with a clean scalp, which is a better surface for a leave-in serum.
- It covers the whole scalp every time you wash.
Where a shampoo falls short:
- Contact time is short, because it is rinsed off.
- How often it reaches your scalp depends on how often you wash.
- It cannot stand in for a leave-in product if you want something that stays on overnight.
Option 3: a hair supplement
A supplement works on a different side of hair care altogether. Topical products look after the scalp environment from the outside, while a supplement supplies nutrients from within. It does not touch your scalp at all, which is exactly why it can sit alongside a serum and a shampoo without any overlap in how they are used.
Hair & Follicle Nutrition is taken as one capsule daily, and the label says not to exceed the recommended dose. Each capsule contains biotin 40mcg, saw palmetto extract 11.11mg, zinc oxide 6.2mg and ferrous gluconate 39.3mg, together with vitamins A, B3, B5, B6, B12, C, D3 and E, fish oil, selenium yeast and copper gluconate. As with any supplement, read the label and take it only as directed. If you are pregnant, breastfeeding or taking prescription medication, talk to your healthcare professional first.
For women, Hair, Skin & Nails provides a different nutritional approach, combining nutrients selected to support healthy hair, skin and nails.
Both supplements can complement topical products such as THRIVE Shampoo and PROSPER Serum, depending on individual needs.
Where a supplement shines:
- One capsule a day is the lowest-effort step of the three.
- It covers the nutrition side that a serum or shampoo cannot reach.
- It fits around any topical routine, because it is taken separately.
Where a supplement falls short:
- It does nothing on the scalp itself.
- It is not a replacement for a varied, balanced diet.
- It is not suitable for everyone without advice first, so the label precautions matter.
Serum vs shampoo: do you need both?
If you are choosing between the two topical products, the deciding factor is contact time. A shampoo is on your scalp for a short time and then rinsed away. A serum is applied after washing and left on overnight. That makes them partners rather than rivals: the shampoo cleans the scalp, and the serum goes onto that clean scalp and stays there.
If you can only commit to one new step, think about which habit you will actually keep. If you already wash your hair regularly and are happy to add a minute or two at night, the serum adds the one thing your shampoo cannot: a step that stays on the scalp overnight. If evenings are chaotic and a new nightly step will not last, switching your usual shampoo for THRIVE is the change that is easiest to keep up.
Topical vs supplement: outside and inside
The second comparison is between what you put on your scalp and what you take by mouth. They are not competing for the same job. Serums and shampoos are about the scalp itself; a supplement is about the nutrients your body has to work with. Adding a supplement does not make a serum unnecessary, and using a serum does not cover nutrition.
This is also why the three CtoMi product pages each suggest using the serum, the shampoo and the supplement together. They are designed as three parts of one routine, not three alternatives to choose between.
How to combine all three in one day
If you decide to use all three, the order matters more than the timing. Here is a simple day that follows every label:
- Take one Hair & Follicle Nutrition capsule at the same time each day, for example with breakfast, so it becomes automatic.
- On wash days, use THRIVE on wet hair, leave it on the scalp for 30 seconds, then rinse thoroughly.
- At night, make sure your hair is dry, then apply one full dropper (1ml) of PROSPER directly to the scalp, focusing on the areas you want to target.
- Massage gently for one to two minutes and leave it on overnight.
- Keep the serum bottle somewhere you will see it at bedtime, because the nightly step is the one most easily forgotten.
Before you start the serum or shampoo, do a patch test on a small area of skin. If you notice any reaction, stop using the product and check with a health practitioner.
Which combination suits you?
There is no single right answer, so match the routine to your situation:
- You want one simple change: swap your everyday shampoo for a hair growth shampoo. It asks the least of you.
- You want something targeted on the scalp: add a serum at night. It is the step that stays on the scalp the longest.
- You already use topical products and want the inside covered: add a daily supplement, after checking the label precautions.
- You want a complete routine: use all three in the order above. Every step is covered in the CtoMi range of hair growth products NZ.
Some changes in your hair are worth checking with a professional before you buy anything. If your hair loss is sudden, patchy, comes with an itchy or sore scalp, or started after an illness, a pregnancy or a new medication, see your GP first. DermNet, the New Zealand dermatology resource, has a clear overview of the different types of hair loss that is useful to read before that appointment.
Frequently asked questions
Can I use a hair growth serum and a hair growth shampoo on the same day?
Yes. The product pages for PROSPER and THRIVE both suggest using them together. Wash with the shampoo first, let your hair dry, then apply the serum at night so it stays on the scalp.
Does the serum go on before or after shampoo?
After. The shampoo is rinsed off, while the serum is a leave-in product. Applying the serum first and then washing would rinse it away before it has had a chance to stay on the scalp overnight.
Do I need a supplement if I already use a serum?
Not necessarily. A serum and a supplement work on different sides of hair care, so one does not replace the other. Whether a supplement makes sense for you depends on your diet and your health, so read the label precautions and ask your pharmacist or GP if you are unsure.
Is a hair growth serum suitable for everyone?
PROSPER is for external use only, and the label recommends a patch test before use. If you have a reaction, stop using it and consult a health practitioner. The label also notes that how well it works can differ from person to person and that hair growth is not guaranteed.
Putting your routine together
Serum, shampoo and supplement are not rivals. The shampoo cleans the scalp, the serum stays on it overnight and the supplement covers the nutrition side. Start with the step you are most likely to keep, then build from there. If the nightly scalp step is the one you are missing, see PROSPER Follicle Booster Serum for the full ingredient list and directions.
